Meet Mark

Let me introduce myself. My name is Mark Sisson. I’m 63 years young. I live and work in Malibu, California. In a past life I was a professional marathoner and triathlete. Now my life goal is to help 100 million people get healthy. I started this blog in 2006 to empower people to take full responsibility for their own health and enjoyment of life by investigating, discussing, and critically rethinking everything we’ve assumed to be true about health and wellness...

For today’s edition of Dear Mark, I’ll be covering three topics. First, salmon and mercury. We’re often told to watch out for mercury in wild fish, but the story is actually more complicated than that. Learn how to tell if wild fish is safe to eat and whether wild salmon should be limited. Next, I discuss the differences between fruit sugar and sugar, or, rather, fruit and sugar. Can fruit be a part of a healthy Primal way of eating despite the sugar content? And finally, I give a few tips to an older woman who’s interested in gaining muscle and strength. I go over exercise, protein intake, as well as the ulterior benefits of resistance training.

Let’s go:

Dear Mark,

I really love fish, especially salmon, and I know they are a great source of Omega 3 so I generally feel good when I’m chowing down on ’em (especially drowned in grass-fed butter!) But I have recently started worrying about possibly eating too much mercury due to my huge fish intake. There have been times when I would have a piece for lunch EVERY DAY. I have read the FDA’s guidelines and such but would like to here from someone I trust about it. My question is how often can I eat fish, especially salmon, without worrying about mercury content? Is once a day way too much? How about 4 times a week?

Thanks for your time

Ripken

The thing to realize about mercury concerns is that the selenium often found in fish binds and renders inert the mercury found in fish. As long as the fish contains more selenium than mercury, you don’t have to worry about mercury toxicity.

I’ve got good news and not so good (but not necessarily bad) news for you. First, the mixed news. Selenium-mercury ratios vary wildly, and official numbers don’t always hold when you look at individual samples of a given species. With many species sold in the United States, even the safe ones, there is high variation and low predictability with regards to selenium and mercury content. However, a study on tropical fish, squid, crabs, and shrimp in the Atlantic Ocean off of Brazil found that most seafood studied had high enough selenium to mercury molar ratios to make them safe for consumption, and find that the longer a fish, the lower the selenium to mercury ratio (higher is better). Still, only seven samples out of 683 taken had unfavorable selenium to mercury ratios.

If you ever get the hankering for shark steaks or king mackerel belly (both very high in mercury with inadequate amounts of selenium), or you’re just worried about the selenium-mercury ratios in the fish you eat, you can always take a selenium supplement alongside the fish. Research shows that selenium supplementation can offset mercury toxicity due to environmental exposure. Residents of a mining town in China with a history of mercury exposure were either given a selenium-producing yeast or an inactive yeast; the ones who got the selenium-producing yeast had increased urinary excretion of mercury and lower excretion of toxins (indicated less mercury toxicity). Supplements aren’t really necessary, in fact, as long as you’re getting enough selenium from your diet. Selenium is richest in Brazil nuts, egg yolks, mushrooms, wild salmon, halibut, and animal kidneys.

As for frequency of consumption, the mercury isn’t a problem as long your selenium outpaces it. If you’re eating wild salmon, you’ll never accumulate enough mercury to be a threat. There are other reasons to limit fish, though. First, although omega-3 fats are vital for your health, they don’t need to be eaten in excess. They’re fragile things that can become oxidized and too many are harmful. Second, overfishing is a valid concern, on both an environmental level (a loss of fish has negative impacts on the marine environment) and a personal level (a loss of fish due to overfishing means less fish available for me or you to eat). A 4-8 ounce serving of fatty fish two or three times a week is probably ideal, assuming you’re avoiding seed oils and processed foods rich in omega-6 fats, which throw off our omega-3:omega-6 balance. That said, if you’re eating a piece of wild salmon every day, you could do a whole lot worse. I wouldn’t worry too much, and I personally wouldn’t stress the mercury.

HI,

I would love to know the truth about eating fruit and how the sugar affects our bodies. How does it differ from white sugar and how much should we really be eating?

Thanks,

MJN

Fruit differs from sugar in several important ways.

First, fruit sugar is a mix of fructose, sucrose, and glucose, with some trace amounts of a sugar alcohol called sorbitol appearing in certain fruits (apples, pears, and many stone fruits, for instance). Sugar, if we’re talking about table sugar, is sucrose – a 50/50 mix of fructose and glucose. The fructose in a peach is the same as the fructose in table sugar. The sucrose in an apricot is identical to the sucrose in table sugar. Where fruit differs is in the ratio of fructose to sucrose to glucose. Depending on the fruit, it might be 22% fructose, 30% sucrose, and 48% glucose, or 30% fructose, 30% sucrose, and 40% glucose. It could really be anything, and the ratio will differ from sample to sample even within a species of fruit, whereas refined sugar is always 50% glucose, 50% fructose.

Fructose is metabolized differently than glucose, being shunted toward the liver for processing. This makes it potentially more hazardous to the liver than glucose, especially when consumed in excess. A recent review covered the fate of fructose in human metabolism and suggested that fructose only modestly contributes to de novo lipogenesis – or the creation of fat from carbohydrate.

While that’s true, the authors give a rather large caveat: “The time periods of liver de novo lipogenesis from sugars and the factors influencing it are not completely understood, and are impacted by the concentrations and tracer characteristics of the various substrates drawn from lipid precursor pools. De novo lipogenesis may also occur in adipose tissue or muscles, but there are no adequate methods available to quantitate it.”

In other words, we only kinda sorta understand de novo lipogenesis in the liver, and we know almost nothing about de novo lipogenesis in fat tissue, nor we do have any way to measure it. They conclude the section on de novo lipogenesis with this assessment: “The influence of fructose consumption on plasma lipids and de novo lipogenesis remains controversial and understudied.”

Meanwhile, studies indicate that fructose overfeeding is way worse than glucose overfeeding in the overweight, increasing LDL particle count, oxidized LDL, and triglycerides while triggering accumulation of visceral/organ fat. Another study in overweight humans found that short term overfeeding with “simple sugars” triggered de novo lipogenesis and increased liver fat in proportion to the increase in de novo lipogenesis. So it seems that the overweight and obese who overeat fructose do experience enough de novo lipogenesis to increase liver fat.

Okay, but that’s just in the overweight and obese, you might say. It doesn’t happen in healthy people eating a normal, hypocaloric diet. True enough. Remember, though: it’s not like the overweight/obese are some niche, fringe group. They’re a whopping 70% of the adult population in America! Most of the United States, then, is likely susceptible to fructose overfeeding. Most of those people are working sedentary jobs, getting inadequate or poorly designed exercise (while overreporting the activity they do get), and eating more sweets and drinking more soda than they require. They aren’t eating hypocaloric diets. They aren’t regularly depleting their glycogen (in fact, obese people tend to have saturated liver glycogen stores). Quite frankly, they aren’t as healthy as they could be. I’m not convinced fructose is harmless in that (sizable) portion of the population. I’m convinced that eliminating simple, refined fructose from their diets is an important step toward getting healthier.

Your question wasn’t about fructose or glucose, though, so I won’t get too far into it. Let’s save it for another time. My point, after all that potentially scary stuff about fructose, is that just because fructose might have some issues doesn’t mean we need to condemn fruit. Fruit is not just fructose, glucose, or sucrose:

It contains fiber, which feeds butyrate-producing gut flora and slows down the digestion of sugar. Butyrate improves insulin sensitivity and fat oxidation (and overall health), while slowing down the digestion of sugar reduces the glycemic impact. There’s even evidence that it can counter the progression of fatty liver, a common consequence of eating refined fructose.

It is more filling than an isocaloric amount of juice or soda. Fruit is just hard to overeat. Just about anyone can drink a quart of soda or juice, but eating fifteen oranges is hard work.

Where people vindicate fructose, they should be vindicating fruit. It’s quite clear that fruit is metabolized differently – and more favorably – than pure sugar, or foods containing refined sugar, even in overweight people for whom regular old refined fructose would be devastating. While the overweight/obese would be best served avoiding refined sugar, research suggests that they can handle modest amounts of fruit (read: not 30 bananas a day) pretty well.

I would like to hear something pertaining to the older generation and how they can gain muscle mass. Most everything for 50+ people is for those who are out of shape and could use a lot of improvement. I’m not out of shape, but would like helpful hints on putting on muscle mass at my age, using Primal [Blueprint] diet.

Vivian

The Primal way of eating will certainly help build muscle – lots of protein, healthy fats (especially animal fats), and adequate amounts of carbohydrate tailored to your activity level will tend to do that. But our skeletal muscle responds primarily to how you use it. Just eating right won’t build muscle alone. If you don’t use it, it won’t increase and will actively atrophy. That’s why bed rest patients lose muscle mass and why your arm looks all spindly when the cast comes off. If you do use it, you will maintain your muscle. If you use it to lift heavy stuff, you will build muscle.

After all, humans are humans, whether young or elderly. We all lay down muscle the same way in response to the same stimulus, just at a different pace. Youngsters with more testosterone can gain mass a lot easier than eldsters, but that doesn’t mean you can’t do it. And even if you can’t pack on tons of muscle (you probably won’t be getting huge), you will maintain your lean mass, which is essential for growing old with grace and ability.

Now, I wouldn’t just rush headlong into an intense lifting program. You don’t want to get hurt. Seek out a trainer for an assessment of your strengths, weaknesses, and limitations.

Alternately, go for something like Dr. Doug McGuff’s Body By Science. It’s designed to be as safe and effective as possible with minimal time commitment. Check out his guest post here, where he lays out the basics of his program, or his blog, where he regularly posts workouts.

If your intestines have corners, you need to get to a GI specialist quickly, preferably through the ER. What is wrong with your stomach that food is getting through in the same manner it went in? And why doesn’t your peristalsis work?

I would like to recommend raising show chickens for older people who are seeking to add to their muscle mass. First, you’ll have a good supply of fresh eggs, but you will also get plenty of exercise lifting those 50 pound feed sacks and dragging them around. The shows are a lot of fun, and not expensive. I got so good and packing feed sacks (and I’m 67) that I bought a pellet stove last year and now I have those sacks to pack around, too.

I’ll be 53 in a few weeks and have been on a muscle gaining program for 5 weeks now. It works! Being over 50 is no impediment to gaining muscle mass. But you do have to eat. And I mean EAT! You can lift weights as hard as you like, but without enough food you won’t gain mass. As Mark said, lots of protein, but also a good amount of carbs, probably a good bit more than you’re used to on a paleo diet. I work out 4 days a week, hit each body part heavy once a week. And one day of sprints. Look at Jim Stoppani’s “Shortcut to Size” program. His diet recommendations are not paleo but you can ignore the specific foods on concentrate on macros. I plan on doing it for 12 weeks then I’ll go back to the more usual primal mode.

First of all, thanks for your books and your website- it is easily the best source of actionable information on diet and exercise on the web. The Paleo Lifestyle is the only way of eating and exercising that truly works and that I can justify scientifically.

That said, it surprised me that you recommended the book “Body by Science” to one of your readers. It is not the first time you do that. IMHO, that book should be called “Body by Bogus Science”. I sincerely hope you know that since the “Body by Science” method is the exact opposite of what we evolved to do. We did not evolved to lift heavy weights excruciatingly slowly. You can’t acquire aerobic fitness doing slow movements as they claim in the book. Nautilus machines are not better than free weights (some are, but very few), etc, etc.

I really wanted Body by Science to be right. What could be better than doing one or two short sessions in the gym instead of the multiple sets conventional training methods recommend. I wanted it to be right so much that I suspended my disbelief, ignored everything that I know about sports physiology, and tried the BBS method for …listen to this … five months.

I followed every single advice in the book, including the one about exercising less frequently if you are not getting results. I became progressively less fit, weaker and lazy. Does it work for some people? Of course it does. If you are out of shape, any exercise is better than no exercise. I am not a gym rat, and I try to exercise as little as I can get away with and stay in good shape (I am 59, 5’11”, 168 lb, 13% body fat). That is weight lifting two or three times a week, occasional bouts of speed and constant movement, just like you recommend.

And I had the exact opposite experience with Body By Science. Following those recommendations has been awesome for me, bigger and stronger than at any point in my life (34 years) and continue to improve. Has fixed my lower back issues, and my cardiovascular fitness in that I can jog significantly longer and at a much increased pace than I could before, this despite running very infrequently. I highly recommend it.

Well I don’t have forty years experience but I certainly wasn’t a beginner when I started. And have been using the Body By Science concepts for 2 years plus and continue to see progress both in strength and body composition.

Thanks for posting this as I got discouraged and confused from going from daily workouts to bbs to nothing at all and getting fat. I was on a yearlong stint of being very fit working out every day and eating paleo and being obsessed with reading about health. I read BBS was convinced and it destroyed me for a year. I got lazier and less fit and started eating like crap. I realized to see the benefits I needed to have fitness as an almost daily habit. I don’t think BBS is bad science, I still think it works absolutely with two caveats. First is it is VERY hard to do it right because of the intensity and focus required.The author admits that and maintains you need someone there pushing you. And you have to stay motivated. For me working out every 5-10 days was ok at first but made me less and less likely to work out as I got out of a habit.

The best 2 things about BBS that I have kept is I try to keep my muscles under strain throughout my sets as much as possible. If I feel I didn’t maximize the fatigue I do another set or two but If I manage to totally tire out the muscle in a set I’ll stop at one. Also overtraining is still an important issue but you really have to be working out hard to get to that point so I don’t worry about it until my body tells me

Well this article is not short on information. Thanks for the selenium-mercy ration insights which I was not aware of. There is a whole lot of scare mongering on mercy, rightly or wrongly so I’ll try to pass this information around.

Protein level is always a little blurred, especially with all the different information out there (Mark I believe you’ve touched on this in the past?). I think the point regarding the fact that higher protein is only necessary is you are breaking down muscle fiber (aka lifting not chronic cardio). Other than that, a higher protein intake alone is not going to increase muscle size. This is probably something that all ages should note, not just 50+.

I have always struggled with muscle gain. Had a bad start as an undiagnosed Celiac sufferer, painfully thin & frail as a child & young adult. I think it set me off on the wrong foot because even being GF for 7 years now, I fear hurting myself (mainly because it still happens easily). I used to love to run, though, being very light on my feet– that probably didn’t help with muscle mass either, though it felt good at the time. I love walking & hoopdance & yoga, but again, not very mass-building.

I do incorporate resistance training now, but whenever I try to ramp it up I end up with an injury that sets me back. It’s very frustrating, & probably the main aspect of PB that I’m not doing right. I will look into the program you recommend as it sounds like an approach that might work for my body type.

I too am coeliac (age 66), and always found it hard to get fit because of the long-term muscle pain following even 1/2 hr of exercise. However, I found this summer that dropping cafeine virtually stops the excessive muscle pain – not what I had expected.

I can now exercise much more effectively. I like following Mark’s e-book exercises, but am also (finally) thinking of getting someone at the local gym to help me get more resistance training – which now shouldn’t cripple me for 10 days at a time!

Regarding the safety of eating salmon and all kinds of fish…I would like to know if radiation on the west coast from Fukushima is affecting pacific fish. There are articles all over the web suggesting fish is now unsafe to eat and the mainstream media does not seem to be covering this subject at all. It has also been suggested that California vegetables are affected by radiation. What’s your take on radiation levels and the effect on the food chain Mark?

Regarding gaining muscle mass at an older age, I would like to recommend yoga, particularly Ashtanga Yoga (sometimes called power yoga). I took my first yoga class at the age of 50 as a birthday present to myself. I was in pretty bad shape from a lifetime of being active but not doing much in the way of regular exercise or sports. I also started weight training sporadically. After a year I joined an Ashtanga yoga club and attended twice a week for a couple of years. I became very strong gaining upper body strength that I’ve never had and very strong legs. I am now 63 and doing Hatha yoga and Tai Chi and the strength I gained in my fifties remains as long as I do sun salutations regularly. I am in better physical shape that I have ever been.

I can build muscle mass fairly quickly, and I am in my 50s. The main thing is to not overdue it at first, and give yourself plenty of recovery time.

Also, quality Creatine, used correctly, can aid in building muscle mass. Mark has an article here somewhere about how to cycle Creatine. The caution is that you should not use Creatine if you have liver issues, or if you drink heavily (as drinking puts a heavy strain on your liver). It would also probably not be a good idea to use Creatine if you are taking a statin drug, as they also are very hard on the liver.

I find it really hard and hilarious to consider myself a “senior” but I am almost 61! I have had no trouble building muscle the past few years when I took up distance cycling. My thighs and calves are pretty impressive I must say! Going ketogenic and adapting my 14-year-old low-carb lifestyle to be basically paleo/primal with only whole foods and no sugar, grain, or starch and 85% fat has been nearly miraculous for me and my almost 72-year-old partner, who also has an amazingly muscular body for his age. This morning, he drank a “bullet-proof” coffee, then went to his gym and did a spin-class followed by a 4000 yard swim. My entire family has insulin-resistance related health issues without carb restriction and I embarked on this journey to prevent the Type II Diabetes that ravaged my father and grandfather and has challenged my sister – pretty significant genetic predisposition for me. However, I have avoided ever having an abnormal fasting blood sugar for 14 years. So, being a trim and well-muscled at my age is pretty phenomenal!

Michelle Obama is one gorgeous, fit 50+ woman. If I can look half as good as her when I’m that age, I’ll take it. Also the 50+ men and women in my bikram yoga class look damn good as well. Perhaps yoga for muscle tone and building muscle mass is the way to go.

Its nice to read a complimentary post about Michelle Obama, as she is a real target for ugly comments at many websites. As a a Chicagoan, I know what a fundamentally decent person she really is, but it is still nice to see. (I hope that neither your comment nor mine attract any of those ugly comments – probably not, as people tend to be nice here, which is one of the many reasons I like MDA).

Plus, as a guy in his early 50s, I don’t mind reading that a younger woman thinks some of the 50 plus guys in her yoga class look “damn good.”

I hope Mark won’t mind but I’m going to blatantly use his amazing platform to get a question answered. I have just been diagnosed with A.S and have been paleo for nearly 6 months. I want to know if by eating non grass fed beef , I’m still eating grain? Here in China , grass fed is not available. Thanks in advance.

Probably not necessary to split hairs to such an extent, unless you are so grain intolerant that a whiff of it from a block away sends you to the ER. Grass-fed is better from an omega-3/-6 point of view. There are supposedly other benefits to grass-fed as well, but if you can’t get it don’t worry about it. Just my opinion.

As someone who was diagnosed with mercury poisoning (skyrocketing levels in both blood and hair) because of eating too much fish, I have to disagree on this one with Mark. Some people have trouble detoxifying, whatever amount of selenium they take. Go to gotmercury.org and use the calculator there. Another point that is frequently overlooked is how much you weigh. Your safe consumption of fish is rather different if you are 90 lbs or 200, or a child.

What are your thoughts on the farmed Atlantic salmon from the company C. Wirthy & Co.? I know in the past you have advised against buying farmed salmon due to its increased likelihood of contaminant, lower omega-3 levels, and diminished taste compared to wild, Alaskan salmon, but they have their farms located in Chile and Norway which, after doing some research, have some of the best farming practices around for salmon. The local megastores have stopped carrying the Wild Alaskan Salmon frozen fillets and Steelhead Trout that they had been supplying for years, and this is the only decent one I can find. What do you advise?

Hey, this is not directly related and slightly after the fact, but apropos farmed salmon from Chile: avoid farmed salmon from Chile at all costs. It’s a horrible gold-rush-style mass-production industry there; salmon is not local to Chile and it has become a new boom that is now seriously affecting the eco-system and harming traditional fishing cultures, apart from producing questionable product (they had a mass contamination of diseased fish there in 2007 due to overcrowded pens and lax standards). Hit up Google for more info 🙂

(Disclaimer before angry Chileans start yelling at me: I love Chile! Yay Chile! Just not… this particular industry. I’ve been there and I’ve talked to people involved on either side and seriously, stick to Norway on that one.)

I’m allergic to basically every source of non-meat fat there is (I try not to eat meat, don’t judge), so I get a lot of my fat intake from dark chocolate. I had a time where I ate a significant amount of fruit at a doctor’s recommendations, but I felt over-carbed constantly, and switching those calories out for dark chocolate made me feel a lot better. I’m operating on about 127g of carbs a day, and I usually get about an hour’s worth of running in, so I’m right in the range I should be on the carb curve.

Anyone have perspective on whether the change in carbohydrate type is terrible for me (read: because the sugars are different), even though it has significantly reduced the total amount of carbohydrates in my diet?

I have the same problems, getting my sugars only from dried fruits in the cold season and fresh fruits in the warm ones – I am from Russia. I don’t get too much time free for running but in this cold winters here in Moscow, I loose a lot of carbohydrates when walking to the office.

Dear Mark, I am fascinated by reading the comments about salmon and about this paleo way of life, which I haven’t tried yet but am interested.

Question1: since I don’t eat meat of any land animals (for ethical reasons) but do eat wild Alaskan salmon, will the salmon be sufficient animal protein for the paleo diet?

Question 2: Since I’m a good cook but not when it comes to fish, I’ve been buying (mainly Trader Joe’s) canned red sockeye wild alaskan salmon, which I find surprisingly delicious and easy to prepare. The only drawback I’m concerned about is the fairly high sodium content (pushes my blood pressure too high) so I rinse it before eating it, but don’t know if that really does any good. Any problem with eating the canned?

My extended family are from the Caribbean islands and when they visit, they like to buy TONS of fruit, so occasionally I binge and eat way more fruit than I know I should, and I still feel great afterwords, and it also doesn’t seem to affect my weight and well-being dramatically. When you eat primal you can really feel the affects of the food you eat, and I definitely feel way better when I eat fruit as supposed to a bag of candy or a processed snack. It’s perfect as an after meal desert, or just to satisfy a sweet tooth in a healthy way.

Mark, I’m a senior (60 years old), and I’m coming out of a long, debilitating illness. Although I’m recovering I have a very long way to go to a full recovery, I experienced a serious loss of lean mass during the illness, from around 150-155 lbs of lean mass to around 110 lbs. I have recovered a little to date, but only to around 125 lbs, which puts me at the physical level I was around the age of twelve. I believe I’ve lost more than just muscle – things such as connective tissue, bone, tendons, organ reserve, etc. I very nearly died back in the Spring. I have been following a primal diet / lifestyle for several months, and I have been making progress, but it has been incredibly difficult to add any significant amount of lean mass. I wondered what suggestions you may have for someone my age who is also a Type II Diabetic (though vastly improved using a primal approach.)